A MODEL DESCRIPTION OF THERMAL EXCHANGE FOR THE NUDE MAN IN HOT ENVIRONMENTS

Abstract

Abstract A theoretical model baaed on the physical laws of heat and moisture exchange is developed to describe the energy exchange between nude man and a hot environment. Equations are presented which express the heat loss from a heated moistened ' skin ' in terms of ambient temperature, humidity and wind. Two different situations are considered; the first where secreted sweat is all evaporated and cooling depends on the amount secreted; and the second, where the skin is wet and cooling limited by the amount of sweat which can be evaporated. In the first case, heat dissipation depends on air temperature and amount of sweat secretion, which varies among individuals. In the second, wet-bulb temperature is shown to be a determining factor, as has already been observed in studying man's tolerance to heat. Graphical presentation is used to demonstrate the individual and combined effects of various environmental factors and to interpret the experimental results of other investigators.